Adding Ocaml bindings for the bitreader as requested by Sarah

Thompson. Usage should be something like this:

open Llvm
open Llvm_bitreader

match read_bitcode_file fn with
  | Bitreader_failure msg ->
      prerr_endline msg
  | Bitreader_success m -> 
      ...;
      dispose_module m

Compile with: ocamlc llvm.cma llvm_bitreader.cma
              ocamlopt llvm.cmxa llvm_bitreader.cmxa


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44824 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm-c/BitReader.h

@@ -0,0 +1,43 @@
+/*===-- llvm-c/BitReader.h - BitReader Library C Interface ------*- C++ -*-===*\
+|*                                                                            *|
+|*                     The LLVM Compiler Infrastructure                       *|
+|*                                                                            *|
+|* This file was developed by Gordon Henriksen and is distributed under the   *|
+|* University of Illinois Open Source License. See LICENSE.TXT for details.   *|
+|*                                                                            *|
+|*===----------------------------------------------------------------------===*|
+|*                                                                            *|
+|* This header declares the C interface to libLLVMBitReader.a, which          *|
+|* implements input of the LLVM bitcode format.                               *|
+|*                                                                            *|
+|* Many exotic languages can interoperate with C code but have a harder time  *|
+|* with C++ due to name mangling. So in addition to C, this interface enables *|
+|* tools written in such languages.                                           *|
+|*                                                                            *|
+\*===----------------------------------------------------------------------===*/
+
+#ifndef LLVM_C_BITCODEREADER_H
+#define LLVM_C_BITCODEREADER_H
+
+#include "llvm-c/Core.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* Reads a module from the specified path, returning a reference to the module
+   via the OutModule parameter. Returns 0 on success. Optionally returns a
+   human-readable error message. */ 
+int LLVMReadBitcodeFromFile(const char *Path, LLVMModuleRef *OutModule,
+                            char **OutMessage);
+
+/* Disposes of the message allocated by the bitcode reader, if any. */ 
+void LLVMDisposeBitcodeReaderMessage(char *Message);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif